Appeal 3367045

The appeal is dismissed.

The description of development provided on the planning application form reads ‘replacement of existing double glazed windows that have suffered rot and decay as a result of being in an inaccessible, river side location, with new self-finished windows with an exact like-for-like section and external appearance’. The Council changed the description to that in the banner heading above. This description is more concise and was used by the appellant for the purposes of the appeal. Consequently, I am satisfied that no party will be prejudiced by my use of it.

The appellant has submitted an additional window detail plan which did not form part of the application1. The plan does not include a substantial difference or fundamental change to the proposal, rather it provides information about the texture of the proposed windows. Having regard to procedural guidance and settled caselaw2, I am satisfied that the interests of any party would not be prejudiced by me taking the additional plan into account.

The evidence confirms the appeal site is in a conservation area and within the vicinity of a listed building. Mindful of the statutory duties set out in section 72(1) and section 66(1) of the Planning (Listed Building and Conservation Areas) Act 1990 (the Act), I have had special regard to the desirability of preserving or enhancing the character or appearance of the conservation area and to preserving the setting of the listed building. 1 [name]: 1162-30 P/DS/01/P2. 2 Section 16 Procedural Guide: Planning appeals – England, updated 18 May 2026; and Holborn Studios Ltd v The Council of the London Borough of Hackney [2017] EWHC 2823 (Admin).

The main issue is whether the proposal would preserve the setting of the [name] listed building, Mill House3; and preserve or enhance the character or appearance of the Cotterstock Conservation Area (the CA).

[address] is a [name] listed stone building located to the north of the appeal site. It dates from 1803 and is a large, three-story detached house set back from the road behind a low stone wall with iron railings above. The list entry describes its double-depth plan, 3-window range and hipped roof with internal ashlar stacks. Built for the owner of [site address] , it has an imposing presence overlooking the [name] and open countryside beyond.

Given the above, and from the evidence before me, I find the special interest and significance of this listed building to be largely attributed to its architectural and historic interest as a good example of a domestic building of status. Important contributing factors in this regard are the use of traditional methods of construction, the building’s surviving historic fabric, its simple architectural composition and the legibility of its historic plan form.

Significance is also derived, in part, from the building’s village setting close to [name], the river and to buildings associated with the former [site address] complex, including the appeal site. [address] sits at a higher land level to the adjacent stone cottages and to [site address] . The intervisibility and former functional relationship between [address] and [site address] alongside and within views of the river and wider countryside positively contributes to the rural context in local views and forms part of the surroundings within which each of these buildings is experienced. This setting contributes positively to the listed building’s significance as a designated heritage asset.

The architectural quality of [site address] also positively complements those of [address]. Although some distance apart and different in scale and appearance, there is a discernible visual affinity between the two buildings, which distinguishes them from the comparably simpler traditional buildings in the area. This is particularly noticeable when approaching the village along [address] from the south, where the buildings are seen together in the same view. Given the relationship between them, I therefore find that [site address] makes a positive contribution to the setting of the [name] listed [address].

The linear village of Cotterstock is surrounded by gently undulating countryside. The eastern part of the village, including [site address] and [address], is within the CA, located close to the [name]. It includes several historic buildings, including the fine medieval [name], and [name], a country manor house built in 1658 and noted for its literary associations. Positioned between these two buildings is a loose ribbon of traditional, predominantly residential, stone properties interspersed behind stone walls and hedges that line [address] and [address]. Whilst the buildings vary in form and design, there is a 3 National Heritage List for England, [name]: 1190116 general consistency of height and use of common materials, including limestone, slate, timber windows and doors, which provides unity to the CA.

Relevant to the appeal, and from the limited information before me and my own observations, the character and appearance of the CA mainly derives from its historic development pattern, vernacular stone architecture, richness of historic buildings and its verdant spaciousness surrounded by open countryside. As a high quality example of a traditional stone former mill owner’s property and as part of the remaining associated and relatively intact former mill building, both [address] and [site address] form a cohesive architectural group that reinforces and positively contributes to the character and appearance of the CA as a whole and thus its special interest and significance as a designated heritage asset.

The proposal seeks the replacement of all the existing timber double glazed windows on the three-storey part of [site address] with double glazed, uPVC windows, with the exception of an elongated window on the rear elevation.

Windows of buildings within the CA, while differing slightly in proportion, are generally painted timber which, with its natural grain and subtle surface imperfections, contributes to the historic interest of the buildings and the character of the CA as a whole.

Despite some alterations to [site address] , it has retained much of its traditional character, including timber windows and doors. I also note the comments of the Parish Council that [site address] is a significant and iconic building in the village. Even if the proposed windows were of high quality and incorporated a similar fenestration pattern and colour to the existing windows, as well as a wood-effect grain, the uPVC would have a more uniform and even finish than painted wood with its surface flaws. Also, uPVC would not age or weather in the same way as wood. The artificial and contemporary appearance of uPVC would be clearly distinguishable from wood and would be an incongruous and inharmonious material on a building with such a well-preserved historic character as this former mill building.

I acknowledge the existing windows were installed in the 1970’s, following a fire at the former mill complex in 1968, and that the appellant has endeavoured to find a close match in terms of the replacement window detailing, including narrow glazing bars and a woodgrain foil finish. However, uPVC is an inauthentic, modern material choice that would result in a synthetic and flat appearance with thicker frames and a chunky meeting rail.

Given the building’s height and scale, the number of windows on each elevation and its prominent location on the approach to the village and directly fronting [address], the proposal would draw the eye to a negative degree. The introduction of uPVC window frames would clearly be out of keeping with the traditional timber materials that characterise many of the historic buildings within the CA.

Whilst the replacement of windows is a relatively small alteration in the context of the CA as a whole, it is these incremental changes to key features which over time, dilute and undermine an area's special interest. I also recognise that change to the setting of a listed building does not automatically result in harm to its significance, and that conservation is an active process of managing change to heritage assets in ways that sustain, reveal or reinforce their heritage interests.

However, the noticeable unsympathetic change in this case would diminish the positive contribution the building makes to the CA and to the setting of [address]. Consequently, it would be harmful to the character and appearance of the CA as a whole and, albeit to a lesser extent, would not preserve the setting, and thus the significance, of the [name] listed [address]. As such, the proposal would fail to meet the requirements of sections 66(1) and 72(1) of the Act.

Paragraph 212 of the Framework requires that great weight be given to the conservation of designated heritage assets, regardless of the level of harm. Consistent with that approach, paragraph 213 sets out that any harm to, or loss of, the significance of a designated heritage asset, should require clear and convincing justification and the magnitude of any harm should be assessed.

The harm to the setting of [address] would be less than substantial and at the lower end of that spectrum given the intervening distance and scale of the proposal. Harm to the significance of the CA would also be less than substantial but towards the lower-to-middle of that spectrum. However, it remains of considerable importance and weight. Paragraph 215 of the Framework advises that this harm should be weighed against the public benefits of the proposal.

There would be economic benefits attributed to the construction and installation of the proposed windows and investment into the property to which I attribute modest weight in support of the proposal. However, this is tempered by the fact economic benefits would also be likely to arise through the replacement of other more appropriate windows or the repair of existing window frames or glazing panels.

The appellant has highlighted energy efficiency gains arising from uPVC windows and increased security through modern locking systems. This could be regarded as a public benefit, at least in part, given the environmental benefits of greater energy efficiency and the social benefits of increasing the availability of energy efficient and secure housing. However, there is no evidence before me to demonstrate that energy efficiency and security improvements cannot equally be achieved through more appropriate measures which would be less harmful to the heritage assets. As such, I have afforded this consideration limited weight.

It is claimed that the existing timber windows are in a poor condition with the sealing vacuum lost in glazing. The appellant argues that uPVC windows would prevent further harm being caused to the building through the deterioration of timber, which could lead to water ingress and internal damage, given the damp microclimate at the site. However, even if scaffolding is required and that timber frame windows require on-going maintenance, such as painting, this in itself should not be considered unreasonable given that buildings in general need on-going maintenance and repair. There is no compelling information before me to indicate that such windows and their maintenance would not meet [name] and Management Regulations.

Furthermore, the longevity of quality timber windows can be effective in time, even in damp areas, which is supported on the basis that the existing older timber window frames are still in place on the appeal property, on other buildings nearby, and in riverside locations across the country. Overall, there is limited substantive evidence before me to adequately demonstrate that the enhancement to [site address] through the replacement of windows could not be achieved by actions which would not be harmful to the significance of the CA or [address].

Drawing all these matters together, a clear and convincing justification for the proposal has not been provided. When taken individually or cumulatively, the collective public benefits would be limited. Consequently, the limited weight that I ascribe to the public benefits which would accrue from the proposal is not sufficient to outweigh the considerable importance and weight that I attach to the harm to the significance of the CA and the [name] listed [address].

I therefore conclude that the proposal would fail to preserve the significance of the [name] listed [address] through harmful development within its setting and the character or appearance of the CA would neither be preserved, nor enhanced. The proposal would conflict with Policy EN12 of the East Northamptonshire Local Plan Part 2 2011-2031, adopted December 2023 and Policy 2 of the [name] 2011-2031, adopted July 2016. Together these policies, amongst other things, seek to protect the historic environment, conserve and where possible enhance the heritage significance and setting of an asset - in a manner commensurate to its significance, and should complement the surrounding historic environment through the form, scale, design and choice of materials.

Conflict also occurs with the Framework, which seeks to conserve and enhance heritage assets through high quality design and the reinforcement of local distinctiveness.

The reason for refusal in the decision notice does not specifically refer to [site address] as a non-designated heritage asset (NDHA). However, the conclusion set out in the Council’s officer report states ‘The proposed replacement uPVC windows would adversely affect the architectural interest of the site as a non-designated heritage asset.’ The appellant’s Heritage Impact Assessment4 also confirms [site address] is a NDHA which may be affected by the proposal. From the information before me and what I saw, I have no reason to disagree with the parties’ conclusions that [site address] is a NDHA, namely, a building which has a degree of heritage significance meriting consideration in planning decisions, but which does not meet the criteria for designated heritage assets. This status provides no statutory protection. [name] am dismissing the appeal for other reasons, I have not considered this matter further as it would not change the outcome of the appeal.

My attention has been drawn by the appellant to examples of replacement uPVC windows recently permitted in conservation areas. At [address], Woodford, the Council granted permission for replacement windows and doors5. However, I note the Council’s officer report in this case records the prevalence of existing uPVC windows along [address]. At [address], Bedford, permission was granted at appeal for, amongst other things, ‘replacement conservation style 4 AHP Heritage Impact Assessment Ref: 24_1470_001 5 North Northamptonshire Council Ref: NE/24/00165/FUL uPVC sash windows’ to a semi-detached dwelling6. [name] note the approach taken by the Inspector in this case, that site is not located in Northamptonshire and the Bedford Conservation Area Appraisal recognised the use of uPVC was not uncommon in the area, which is not the case in this appeal. As such that Inspector’s conclusions and reasoning have limited comparability to this appeal.

The circumstances of these examples are not sufficiently similar to the appeal before me to weigh in its favour. Whilst consistency of decision making is important, the circumstances in each case are likely to be different, and in any event, the fact that apparently similar development has been granted permission is not a reason, on its own, to allow unacceptable development. I have considered this appeal proposal on its own merits and concluded that it would cause harm for the reasons set out above.

There is support for the proposal from Cotterstock Parish Council. Nonetheless, support for a proposal does not indicate a lack of harm and I have set out above why the proposal does not preserve the setting of the listed building or the character or appearance of the CA.

For the above reasons the proposal conflicts with the development plan taken as a whole and there are no material considerations including the Framework that would justify a decision other than in accordance with the development plan.

I therefore conclude that the appeal should be dismissed.